<style type='text/sass'>

    @mixin border-radius($radius) {
        -webkit-border-radius: $radius;
        -moz-border-radius: $radius;
        -ms-border-radius: $radius;
        border-radius: $radius;
    }

        #awesome {
            width: 150px;
            height: 150px;
            background-color: green;
            @include border-radius(15px);
    }
</style>

<div id="awesome"></div>
